Garden Talk: October 11, 2007

From NGA Editors

Striking Purple-Leaved Pineapple Lily

Pineapple lily (Eucomis comosa) is a subtropical plant that produces sword-like leaves and pineapple-like flowers. Its hardy only in USDA zones 7 to 10 but can be grown as an annual in colder climates. While many pineapple lilies have green foliage, a few sport darker colored leaves, and one of the best is the variety Oakhurst.

Not only does Oakhurst feature deep purple leaves, in midsummer it produces pink-purple flower stalks in the shape of mini-pineapples. The flowers are excellent for cutting, lasting up to six weeks in a vase. Oakhurst grows best in full sun, is heat tolerant, and forms a clump 2 feet tall and wide at maturity. It makes a great container plant and in northern climates can be overwintered in a protected garage or shed, or grown indoors as houseplant.

Identify Your Plants Via E-mail

It happens even to the most knowledgeable gardeners: You see a plant you like but you don't know the name of it, and your gardening friends don't know what it is either. Sometimes even a local Master Gardener or garden center employee cant figure it out. So where do you go to identify the plant?

The Lady Bird Johnson Wildflower Center at the University of Texas, Austin, has a solution. They have a new program called "Mr. Smarty Plants." You can ask questions online for free and send them digital images of your mystery plant to identify. They ask for your geographic location, the site where you found the plant, and a number of images of details such as leaves, stems, flowers, fruit, as well as the entire plant.

New, Stronger String Trimmer

Cutting weeds and edging grass with a string trimmer is a thankless job, yet many homeowners like the manicured look that these machines afford. One of the most annoying aspects of using string trimmers is replacing strings that break when they contact hard surfaces such as rocks and fences. A new string trimmer boasts a design that reduces the breakage problem.

The Pivotrim is a string trimmer head featuring a unique design that allows the string to rotate and pivot when it comes in contact with a hard surface, reducing the chance that the string will break. The head also features a different string-loading mechanism. Instead of winding the nylon string around a spool and threading it through a small hole, you simply push the two ends of a pre-cut piece of string through two holes and pull tight. The string automatically locks into place.

The manufacturer claims the Pivotrim head fits on 99 percent of the gas trimmer models on the market.

Will Biofuels Help Reduce Global Warming?

Biofuels are all the rage. With soaring oil prices and a desire to reduce our dependence on foreign energy resources, there's a lot of interest in growing corn and other crops to be processed into fuel, such as ethanol. Also, many believe that burning biofuels will reduce carbon dioxide emissions and slow global warming. While biofuels can reduce our dependence on foreign oil, new research raises questions about whether they will help slow global warming.

Much of the concern about global warming has been focused on carbon dioxide, but nitrous oxide has been found to have 300 times the warming potential of carbon dioxide. Corn and other biofuel plants that need high nitrogen levels for growth generally release high nitrous oxide levels into the atmosphere when burned, so researchers wondered about their potential impact on global warming.

The scientists investigated the amount of nitrous oxide produced by corn, rapeseed, and other plants commonly used as biofuels. They found that these plants had more potential for contributing to global warming than offsetting it because of the nitrous oxide they emit. The scientists calculated that growing nitrogen-rich plants as biofuels could result in a zero net gain in reducing global warming and might even increase the warming. Plants that require less nitrogen and therefore release less nitrous oxide might be better choices for biofuel.